No abstract

Objective: Neuroendocrine abnormalities, such as activation of the hypothalamic-pituitary-adrenal (HPA) axis, are associated with obesity; however, few large-scale population-based studies have examined HPA axis and markers of obesity. We examined the cross-sectional association of the cortisol awakening response (CAR) and diurnal salivary cortisol curve with obesity. Design and Methods: The Multiethnic Study of Atherosclerosis Stress Study includes 1,002 White, Hispanic, and Black men and women (mean age 65 6 9.8 years) who collected up to 18 salivary cortisol samples over 3 days. Cortisol profiles were modeled using regression spline models that incorporated random parameters for subject-specific effects. Cortisol curve measures included awakening cortisol, CAR (awakening to 30-min postawakening), early decline (30 min to 2-h postawakening), late decline (2-h postawakening to bedtime), and the corresponding areas under the curve (AUC). Body mass index (BMI) and waist circumference (WC) were used to estimate adiposity. Results: For the entire cohort, both BMI and WC were negatively correlated with awakening cortisol (P < 0.05), AUC during awakening rise, and early decline and positively correlated to the early decline slope (P < 0.05) after adjustments for age, race/ethnicity, gender, diabetes status, socioeconomic status, bblockers, steroids, hormone replacement therapy, and smoking status. No heterogeneities of effects were observed by gender, age, and race/ethnicity. Conclusions: Higher BMI and WC are associated with neuroendocrine dysregulation, which is present in a large population sample, and only partially explained by other covariates.

Shortened sleep related to adverse social environments represents one potential pathway through which neighborhoods may influence health.

Socioeconomic and psychosocial factors have been found to be associated with systemic inflammation. Although stress is often proposed as a contributor to these associations, no population studies have investigated the links between inflammation and biomarkers of stress. The current study examines associations between daily cortisol profiles and inflammatory markers interleukin-6 (IL-6), interleukin-10 (IL-10), and tumor necrosis factor (TNF-a) in a population-based sample of 869 adults with repeat measures of cortisol over multiple days. Persons with higher levels of IL-6 had a less pronounced cortisol awakening response, a less steep daily decline, and higher cortisol area under the curve for the day with associations persisting after controls for risk factors and other cytokines. Persons with higher levels of TNF-a had lower cortisol levels upon waking, and flatter daily decline, although associations with decline were attenuated when controlling for inflammatory risk factors. Higher levels of IL-10 were associated with marginally flatter daily cortisol decline (p < .10). This study is the first to identify associations of basal cortisol activity and inflammatory markers in a population-based sample. Findings are consistent with the possibility that HPA axis activity may mediate associations between psychosocial stressors and inflammatory processes. Additional prospective data are necessary to clarify the directionality of associations between cortisol and inflammatory markers.

Interventions focusing on the psychosocial stressors associated with economic deprivation during any period from infancy to adulthood may be helpful, but targeting interventions across multiple periods may have the greatest impact. Interventions aimed at improving economic conditions between infancy and early adulthood may have implications for long-term changes in HPA axis functioning.

Racial and ethnic differences in diurnal cortisol rhythms are stable over time. However, the magnitude of changes in cortisol levels associated with chronic stress levels may vary by racial and ethnic subgroups.

Our findings do not support the hypothesis that differences in level or diurnal pattern of salivary cortisol output are associated with MetS among persons without clinical diabetes.

Previous studies have yielded equivocal findings on the relationship between personality and cortisol activity. The present study examined associations between personality and cortisol activity in a large, diverse adolescent sample, while partialling the effects of relevant demographic and health-related covariates. A subsample of 230 participants (57% of whom reported elevated neuroticism) was selected from a larger sample of 16-to 18-year-olds involved in a study on risk factors for emotional disorders. Subsample participants completed a battery of personality questionnaires, and saliva collection was requested several months later on three consecutive days at six time points per day, from wakeup to bedtime. Associations between personality and cortisol rhythms were examined using multilevel growth curve modeling. Neuroticism (N) and introversion (I) were significantly and differentially associated with features of diurnal cortisol patterns. Specifically, a significant N by gender interaction was observed, demonstrating flatter cortisol rhythms across the waking day among male participants with higher N. Elevated I, however, was associated with lower cortisol awakening responses for both male and female participants, and higher cortisol at the time of waking for male participants only. The present study supports personality as a significant predictor of diurnal cortisol patterns in late adolescence, after accounting for the effects of demographic and health covariates, and suggests that gender plays a role in moderating associations between personality and cortisol. Keywordscortisol diurnal rhythms; HPA activity; personality; neuroticism; introversion; gender; adolescence In the search for risk factors of mood and anxiety disorders, there has been a burgeoning interest in the role of neuroticism (N), a relatively enduring personality trait associated with a proneness to experience negative emotions and thoughts (e